Process for the production of carbon disulfide



E. HALM Oct. 26, 1954 PROCESS FOR THE. PRODUCTION OF CARBON DISULFIDE Filed Aug. 8, 1951 Patented Oct. 26, 1954 OFFICE PROCESS FOR THE PRODUCTION OF CARBON DISULFIDE Eduard Halm, Bern, Switzerland Application August 8, 1951, Serial No. 240,894

Claims priority, application Switzerland August 14. 1959 2 Claims.

This invention relates to a process for the pro duction of carbon disulphide.

For the production of carbon disulphide, elec tric shaft-furnaces employing two electrodes placed one above the other, are commonly used. Between the electrodes, carbon (e. g. charcoal or oil-coke) is heated. The sulphur is introduced in the vicinity of the lower electrode, at one point only. Over the lower electrode, a pool of sulphur collects which cools the base of the furnace. This sulphur pool must reach a certain level above the floor of the furnace, in order that the correct quantity of sulphur may vaporise in a given time and combine with the charcoal to give carbon disulphide. Should the sulphur pool be too low, too little sulphur vaporises and the upper area of the furnace overheats. If the level is too high, too much sulphur vaporises and the course of the reaction is incomplete. In addition, it is well known that, when the correct level of this sulphur pool is exceeded, the column of carbon in the furnace may be detached from the lower electrode by floating on the sulphur, resulting, of course, in interruption of the electric circuit in the furnace. Moreover, the distribution of temperature in the upper region of the fire-clay lining of such shaf -furnaces is rarely symmetrical or constant. Overheating frequently occurs at different points, damaging the lining or necessitating a reduction in output.

The object of the present invention is to provide a process whereby, firstly, the level of the sulphur pool is reduced and the danger of the electric current being interrupted thereby obviated or mitigated, and, secondly, overheating in the upper region of the furnace is prevented.

The process or the present invention may be described as follows. The sulphur, in the liquid state, is introduced from without through the furnace-wall at several points in the upper section of the furnace, flowing down the inner-Wall. In this way, the sulphur is heated, cooling simultaneously the inner-wall of the furnace. In the processes in general use at the present time, the inner-wall of the upper part of the furnace has temperature within the range TOW-930 0., which is often exceeded at various points, but by the process of the present invention, temperatures of between 300 and. 500 C. may be maintained. For example, six feed-points may be arranged symmetrically around the entire circumference of the furnace. By arranging the distribution of sulphur quantities passing through these feed-points, overheating can be avoided without difficulty. Most of the sulphur collects in a pool in the lower part of the furnace, in which it is heated to the point of vaporising. The sulphur vapour rises through the column of charcoal and is converted to carbon disulphide.

By reducing the maximal temperature of the furnace-wall, the fire-olay lining is, of course. greatly preserved and its life extended considerably. In addition, the lesser dii'ference in temperature between the innerand outer-wall re sults in lower heat-loss i. e. greater economy.

Whilst the sulphur is flowing from the upper section of the furnace down the inner-wall to the floor, it acquires such a great quantity of heat that little further increase in temperature is required to raise it to boiling point. The required level of the sulphur pool is thereby much reduced, being approximately half as high as the level necessitated by feeding the sulphur directly at the basev Production management is fundamentally simplified by this process, because the dangers of overheating and of interruption to electric current are rendered practically impossible.

The electric furnace illustrated in the figure of the drawing gives an example of the process in operation. t consists of a fire-clay lined shaft l with sheet-metal casing 2. On the waist 3, likewise lined, three hollow bodies 4- are situated, forming collectively the upper electrode. Each consists of four iron tubes superimposed, through which water is fed at 5 for cooling purposes, and is withdrawn at 6. 7 represents the cable for electric current. The lower electrode 8 consists of an iron plate lying horizontally on the floor of the shaft. 9 the feed-point for maintaining the level of charcoal. Liquid sulphur is introduced through the feed-points it and flows down the innerwvall, thereby cooling the same. There are preferably six feed-points equally spaced around the perimeter of the shaft. The sulphur collects on the pool H, where it is heated until it vaporises. The sulphur vapour rise through the charcoal charge 12 and is converted into carbon disulphide. The gaseous products leave the furnace at [3. The opening I is intended for the removal of Waste and clearing of the furnace.

The process may, or course, be operated in a furnace of different construction. The upper electrode may, for example, be of circular or of frameconstruction or may consist of a vertical graphite rod.

What I claim is:

1. A process of producing carbon disulfide in an electric shaft furnace having side walls and 3 being heated by an electric current passing between 2. first electrode at the bottom of said furnace and a second electrode above said first electrode through a charge of carbon particles located between said electrodes, comprising the steps of introducing molten sulfur into said furnace at a plurality of points paced about the periphery of said furnace through the upper part of said side Walls so that said molten sulfur flows down along the inner surface of said side walls as a film cooling said side walls and forming a pool of molten sulfur at the bottom of the side walls of said furnace over said first electrode, said sulfur vaporizing at the surface of said pool due to the heat in said furnace and rising through 15 said carbon charge, forming carbon disulfide; and recovering the thus-formed carbon disulfide.

2. A process of producing carbon disulfide in an electric shaft furnace having side walls and being heated by an electric current passing between a first electrode at the bottom of said furnace and a second electrode above said first electrode through a charge of carbon particles located between said electrodes, comprising the steps of introducing molten sulfur into said furnace at a plurality of points spaced about the periphery of said furnace through the upper part of said side walls between said electrodes so that said molten sulfur flows down along the inner surface of said side walls as a film cooling said side walls and forming a pool of molten sulfur at the bottom of the side walls of said furnace over said first electrode, said sulfur vaporizing at the surface of said pool due to the heat in said furnace and rising through said carbon charge, forming carbon disulfide; and recovering the thus-formed carbon disulfide.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 702,117 Taylor June 10, 1902 805,501 Taylor Nov. 28, 1905 805,502 Taylor Nov. 28, 1905 1,312,800 Moore et a1. Aug. 12, 1919 1,849,140 Dow Mar. 15, 1932 2,046,818 Harkness July '7, 1936 2,200,475 Legeler May 14, 1940 2,481,411 Grace et a1. Sept. 6, 1949 FOREIGN PATENTS Number Country Date 898,663 France May 3, 1945 

1. A PROCESS OF PRODUCING CARBON DISULFIDE IN AN ELECTRIC SHAFT FURNACE HAVING SIDE WALLS AND BEING HEATED BY AN ELECTRIC CURRENT PASSING BETWEEN A FIRST ELECTRODE AT THE BOTTOM OF SAID FURNACE AND A SECOND ELECTRODE ABOVE SAID FIRST ELECTRODE THROUGH A CHARGE OF CARBON PARTICLES LOCATED BETWEEN SAID ELECTRODES, COMPRISING THE STEPS OF INTRODUCING MOLTEN SULFUR INTO SAID FURNACE AT A PLURALITY OF POINTS SPACED ABOUT THE PERIPHERY OF SAID FURNACE THROUGH THE UPPER PART OF SAID SIDE WALLS SO THAT SAID MOLTEN SULFUR FLOWS DOWN ALONG THE INNER SURFACE OF SAID SIDE WALLS AS A FILM COOLING SAID SIDE WALLS AND FORMING A POOL OF MOLTEN SULFUR AT THE BOTTOM OF THE SIDE WALLS OF SAID FURNACE OVER SAID FIRST ELECTRODE, SAID SULFUR VAPORIZING AT THE SURFACE OF SAID POOL DUE TO THE HEAT IN SAID FURNACE AND RISING THROUGH SAID CARBON CHARGE, FORMING CARBON DISULFIDE; AND RECOVERING THE THUS-FORMED CARBON DISULFIDE. 